Field of the Invention
The present invention relates to wireless communication and more particularly, a method for setting a starting position of a data channel in a wireless communication system and apparatus using the method.
Related Art
A wireless communication system is capable of transmitting a control and a data channel simultaneously within one time interval, for example, one subframe, which is a scheduling unit. The control channel transmits control information, which includes a physical downlink control channel (PDCCH) transmitting downlink scheduling information and uplink scheduling information. The data channel transmits control information and/or data, which includes a Physical Downlink Shared Channel (PDSCH) and a Physical Uplink Shared Channel (PUSCH).
The amount of radio resources occupied by the control channel and that occupied by the data channel can be varied for each subframe. It is common in the Long Term Evolution (LTE) system that the area in the time domain occupied by the control channel is figured out through a Physical Control Format Indication Channel (PCFICH), and a terminal considers an area within a subframe excluding the area occupied by the control channel as the area occupied by the data channel.
Meanwhile, in a wireless communication system, a data channel located in one time interval (for example, a subframe) can be scheduled through one control channel, or a data channel spanning a plurality of time intervals can be scheduled through one control channel. In the latter case, for example, a control channel transmitted at a subframe n can include scheduling information for scheduling data channels spanning subframes n to n+m (where m is a natural number larger than 1).
In this case, a terminal attempts to figure out a starting position of a data channel of each subframe by decoding a total of m+1 PCFICHs from subframes n to n+m. If a decoding error occurs in any one of the m+1 PCFICHs, however, the starting position of the data channel in the corresponding subframe will be incorrectly identified, and as a result, all of the data from the subframes n to n+m may not be decoded properly.